A new report reveals the programme is counter-productive and causing great harm to civilians and US national security.

The US' official line is that its drone strikes are precise and successful in their mission to attack those deemed to be a threat to the US.

Barack Obama, the US president, said: "Actually drone attacks have not caused a huge number of civilian casualties. For the most part they have been very precise, precision strikes against the al-Qaeda…"

But a new report Living under drones released by human rights researchers at Stanford and New York universities says the US' official narrative is simply false, and that many civilians have been killed and injured.

"We interviewed 130 people in Pakistan including 70 with direct experience with drones… What we found most surprising were these undocumented effects on everyday life holding entire communities in a state of real terror."

- Omar Shakir, Living under drones researcher

Due to the remoteness of attack locations and government secrecy, exact figures are hard to come by.

But the report judged the most credible figures to be from 474 to 881 civilians killed by drones between June 2004 and September 2012, in Pakistan alone.

It also points out that the number of "high-level" targets killed as a percentage of total casualties stands at two per cent.

The report finds that the drone programme is "facilitating recruitment to violent non-state armed groups, and motivated further violent attacks".

Researchers who worked on the Living under drones report relied on the Foundation for Fundamental Rights, a Pakistani human rights group, to find interview subjects.

In a recent poll the Pew Research Center found that 74 per cent of Pakistanis now consider the US an enemy.

The Bureau of Investigative Journalism reports that out of the approximately 3,300 people killed in drone strikes in Pakistan, at least 176 are reported to be children.

"The US government doesn't brief people about drones in Pakistan. There may be people who leak information [but] this is a covert programme. It's illegal to acknowledge that it happens, it's illegal to talk about specific persons."

- Christine Fair, an assistant professor, Georgetown University

The US has only recently formally acknowledged its drone programme.

In April, John Brennan, the US chief counter-terrorism advisor, discussed the use of unmanned aircraft at the Woodrow Wilson Center, saying: "There is no more consequential a decision than deciding whether to use lethal force against another human being, even a terrorist dedicated to killing American citizens. So in order to ensure that our counter-terrorism operations involving the use of lethal force are legal, ethical and wise, President Obama has demanded that we hold ourselves to the highest possible standards and processes.

"This reflects his approach to broader questions regarding the use of force. In his speech in Oslo when accepting the Nobel Peace Prize, the president said that "all nations, strong and weak alike, must adhere to standards that govern the use of force".

So what are the consequences of the US drone programme?

To discuss this on Inside Story Americas with presenter Shihab Rattansi are guests: Omar Shakir, one of the researchers who worked on the Living under drones report who conducted many interviews in Pakistan's northwest; Christine Fair, and assistant professor at the Center for Peace and Security Studies at Georgetown University; and Robert Grenier, a former director of the CIA's counter-terrorism center.

"The insurgency in Afghanistan has become worse. There's a much larger number of individuals who are transiting across the border from Pakistan to attack NATO, US and Afghan forces. So a tool which was initially used for counter-terrorism has now become a counter-insurgency tool."

Robert Grenier, a former director of the CIA's counter-terrorism center

Living under drones report:

There is significant evidence that US drone strikes have injured and killed civilians even though the US government rarely acknowledges this.

The hovering of drones 24-hours a day over communities terrorises residents and has a devastating impact on social and economic life, which includes symptoms of intense psychological trauma among the civilian population.

The evidence that the strikes have made the US safe overall is ambiguous at best. The strikes have stoked hostility toward the US and motivated further violent attacks on US targets.

The drone strikes undermine respect for the rule of both international and domestic US law. There are doubts on the legality of strikes not targeted at individuals linked to the 9/11 terror attacks or those who do not pose an immediate threat to the US.

The report highlights the US government's failure to ensure basic transparency and accountability for the programme, or to set out the legal basis for operational rules.

The drone strike policy may establish dangerous precedents for other governments who want to use lethal force.